This invention relates to a robot control apparatus for controlling a plurality of autonomous mobile robots, and more particularly to a robot control apparatus allowing a plurality of autonomous mobile robots to move without colliding with each other.
In a robot control system, a plurality of autonomous mobile robots (hereinafter referred to as “robots”) are under control of a robot control apparatus that allows these robots to perform a variety of operations, such as a porter's service, a receptionist's service and a guide service, in a desired manner. Such operation(s) will be hereinafter referred to as “task(s)”. It is generally assumed that a task is carried out in a predetermined task-execution area, such as a business office and a private house. When a number of robots move in a single task-execution area, particularly in a complex area, such as a business office and a private house, etc., any robots may possibly come upon an obstacle. Especially, in cases where the obstacle is another robot, the robots would collide with each other. With this in view, several approaches have been proposed for preventing robots from colliding with each other.
For example, JP 5-66831 A (see paragraphs 0008-0014; FIG. 4) discloses a robot system, in which robots are configured to detect nodes provided on their moving route, so as to move by aiming sequentially toward each detected node as a subsequent destination. In this robot system, each robot requests a robot control apparatus to allow a reservation for its exclusive use of a node detected in its moving route. In response to the request, the robot control apparatus determines whether the request for reservation is to be allowed, based upon the presence or absence of a prior request recorded for the same node, and if the request is allowed, the robot then moves toward the node for which its request is allowed.
Another approach as disclosed in JP 8-63229 A (see paragraphs 0012-0027; FIG. 3) configures robots to communicate with each other so as to prevent the robots from colliding with each other.
However, in the former approach (the robot system disclosed in JP 5-66831 A), for example, when a robot supposed to carry out a task of lower priority at a specific node has requested a reservation for that node earlier, another robot which submits a reservation request for the same node later is unable to make a reservation for that node, with the result that the robot submitting the belated request, which would be supposed to carry out a task of higher priority at the same node, would disadvantageously become unable to timely go to the node. In short, movement of each of the plurality of robots cannot be optimized. Further, since the robots have to make a reservation for a node before going to the node, processing for communication between each robot and the robot control apparatus would become complicate and burdensome.
The robots in the latter approach, as disclosed in JP 8-63229 A, are not capable of adjusting to changes in priority of the tasks, and thus its collision prevention operation would not be optimized. In addition, the operation implemented in each robot for preventing collision with another robot is a predetermined routine one, and thus would not be able to be optimized so as to conform to the topographic features of areas in which the robot would move.
There is a need for eliminating the aforementioned disadvantages, and it would thus be desirable to provide a robot control apparatus capable of optimizing movements of a plurality of robots.
Illustrative, non-limiting embodiments of the present invention overcome the above disadvantages and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantages described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any of the problems described above.